The Didache is the earliest known document outside the NT to identify the problem of settled faith communities in conflict with traveling, itinerant preachers and prophets. The Didachist does not doubt the validity of such persons, but recognizes that not all of them are worthy witnesses to the teachings of Jesus of Nazareth. Those who teach falsely for their own gain are identified as "Christ peddlars," a term known first from the Didache